The Large Hadron Collider (LHC) is a particle collider built by CERN for testing the predictions of theories within high energy physics, thereby contributing to advancements in our understanding of physical laws. In order to improve the discovery potential of the collider, the LHC will undergo an upgrade to be able to reach luminosities of 5x10³⁴ cm²s^-1 and the increased collision rate following the upgrade facilitates the need for a new readout system for the ATLAS experiment at the LHC that meets the challenging demands on low mass, high-speed readout capability and radiation tolerance, something which is especially important for the pixel detector closest to the particle interaction point. This work describes preparations of the ATLAS pixel detector for the phase 2 inner tracker upgrade, in the form of testing and verification of new readout techniques and recently developed pixel chip prototypes, as well as characterization and simulation of a data transmission link for high-speed readout of the pixel front-end chips. Equally as important as the development of improved readout electronics for an upgraded system is the maintenance of the present ATLAS detector hardware, as well as detailed simulations of the detector operation. This thesis also covers work related to the update of a test bench system for one of the calorimeters of the ATLAS experiment, and the simulation of radiation damage effects in the pixel sensors.